Concrete cement composition



/ ma as EXAMINER United States Patent 3,202,520 Patented Aug. 24, 1965 weight percentage of between about} to 18 weight per- 3,202,520 cent, and preferably about 9 weight percent. As with CONCRETE CEMENT COMPOSITION Charles R. Enoch, King of Prussia, Pa., assignor to Resco Products, Inc., Norristown, Pa., a corporation of Pennsylvania N0 Drawing. Filed Mar. 2, 1964 Ser. No. 348,789

4 Claims. (Cl. 10

The present invention is directed to a concrete cement composition, and more particularly to a concrete cement composition which is pic. In particular, the present invention is directed to an improved concrete cement composition comprising phosphoric acid and alumina.

Concrete cement compositions comprising phosphoric While the present invention is directed to the concrete acid and alumina have been suggested, and have proved cement composition rather than to the concrete, generto be very useful. Unfortunately, these prior composially the concrete cement compositions of the present intions suffer from a major failing which has seriously vention may form from to 30 weight percent of the hindered their utility. Thus, prior concrete cement comconcrete with the aforesaid or similar' aggregates formpositions formed from phosphoric acid and alumina have 20 ing the remainder. At the time of usage of the concrete, tended to be hygroscopic. Furthermore, these prior comthe user will add wwin the gmguntJ-li from-l..topositions have required an appreciable period of time, 8 weight per e nt, and then ca's't'the concrete blend. The i such as from overnight to 24 hours or more in which to cast concrete blend will be non-hygroscopic, and will set set. This is a serious handicap in many applications, as rapidly. While the setting time will vary depending upon where there is exposure to moisture after the application 25 the ambient temperature conditions, it will generally be of the concrete cement composition, or where the conless than about two hours. Concrete, of the aforesaid crete cement composition is used for patching. In additype, may be applied by a trowel, and also by a pneumatic tion, prior concrete cement compositions formed from gun or pneumatic ram. phosphoric acid and alumina could not be readily applied The compositions of the present invention should be using a pneumatic gun or pneumatic ram. prepared by-dry blending the magnesium oxide into a This invention has as an object the provision of a novel powdered composition. Thus, where the concrete ceconcrete cement composition comprising phosphoric acid ment composition of the present invention is prepared as and alumina. such, the phosphoric acid and alumina may be blended,

This invention has as another object the provision of a as at room temperature, with the alumina added to the concrete cement composition which is non-hygroscopic, liquid phosphoric acid. The resultant mixture should be and which will set in a relatively short period of time, dried at. atemperature above 212 F. for a sufiicient such as up to about twg hours. time to remove all moisture,. such as at 230 F. for. a

This invention has as ytfinother object the provision minimum of 30 minutes. The so-dried mixture should of a novel concrete cement composition which may be then be pulverized or otherwise treated to produce a fine applied through a pneumatic gun or pneumatic ram or the like.

Other objects will appear hereinafter.

These and other objects are accomplished by the concrete cement composition of the present invention which consists essentially of plpsphorirnagid, alu mina, and mpg nesium oxide.

e p osp oric acid is used in its liquid state. The exact chemical nature of the phosphoric acid and its concentration are not critical. Thus, I have successfully used both ortmaphgs hgric acidandmolyphospborieacid in the compositions of the present invention. Furthermore, I have used ac 'd containing from. 15 LO 50 weight percent or more of water. However, the phosphoric acid shon'ldbe'presentl'ntheconcrete cement composition of the present invention in a sufiicient concentration so that from 15 to 55 weight percent of the concrete cement composition constitutes phosphorous pentoxide, namely P 0 when the composition is quantitatively analyzed.

crete cement gomposition gf the present invention shgpld Preferably, theampnLoflphesphoric acid in t h e con;

carbide, silica, chromium oxide, calcined cla s, tabular alumina, or mixtures of the foregoing. The concentration of these aggregates in the concrete will vary depend-, ing upon the qualities sought in the finished concrete.

powder, as for example a powder capable of passing through a 325 mesh screen. The finely divided magnesium oxide should then be dry blended with the finely divided powder.

If desired, the phosphoric acid, alumina, and concrete aggregates, such as the aforementioned silicon carbide, silica chromium'oxide, clays, and/or ferric oxide may ml ended, then dried at a temperature such as 230 F. for a minimum period of 30 minutes in order to drive off moisture, and then pulverized. The magnesium oxide may be added by dry blending to this powdered mixture, with the weight percentage of the magnesium oxide be ing based upon the P 0 of the phosphoric acid, and of the alumina in the concrete cement components, as aforesaid.

By way of illustration, there is set forth below examples of the concrete cement compositions of the pres ent invention. These examples are by way of illustration, and can be varied in accordance with the disclosure set forth above. In each instance, the concrete cement composition was prepared by dry blending finely powdered magnesium oxide into a finely powdered mixture of phosphoric acid and alumina which had previously been blended together by having the alumina added to 5 the liquid phosphoric acid, followed by drying at a suflipositions containing .iitojlweighmmina.

esi QXide should be present in the con crete cement compositions of the present invention in a cient temperature and for a sufficient period of time to remove all moisture and subsequent pulverization of the dried material:

Example 1 A concrete cement composition derived from 50 weight percent orthophosphoric acid and containing in the final state 33 weight percent P 57 weight percent alumina, weight percent alumina. The inert extender ma be coand weight percent magnesium oxide. mingled with the alumina powder as by dry blending, or

Example 2 the inert extender may be deposited upon the alumina.

However, the jngrLextendewuch as sil should not re- A concrete cement compositwn wntamms 27 welght 5 act with the phosphoric acid, nor stTaTi'lii ii interfere with percent P 0 derived from 60 Weight Percent P the reaction between the phosphoric acid and the alumina.

Phofic acid, 63 Wfiight Pefcfllt alumina, 6 Weight Percent The present invention may be embodied in other specific magnesium oxide, 3.5 weighgpercept silica, 0.5 We g forms without departing from the spirit or essential atpercent ferric oxide. This concrete cement composition t ib t th f d, accordingly, f r nc should b is derived from an alumina containing the aforesaid silica 10 d t th appended claims, rather than to the foregoing and ferric oxide impurities. specification as indicating the scope of the invention.

I claim:

Exampl e 3 1. A concrete cement composition suitable for blending A Concrete cel'nent COmPOSIT-IQI} contamlflg 2O Welght with aggregate to prepare rapid setting concrete which D 2 5 deflvfd from 75 welgilt Percent T P will set within about two hours to yield a non-hygroscopic P 301d, 8) Pemfint alumma: and 6 welght cast concrete, said composition consisting essentially of 851111 magneslum oxldea uniform blend of a mixture of a phosphate derivpd from Example 4 phosphoric acid an 13m aIurnina ,..and containing from A concrete cement composition containing 45 weight 19355 Wei-Sm Percent Of 9 and from 45 to 75 Weight percent P 0 derived from 85 weight percent orthophos- 1 1111 3 and from 5 to 18 Right Percent of phoric acid, 49 weight percent alumina, and 6 weight perw Oxide- I cent magnesium oxide. 2. A concrete cement composition in accordance with Example 5 claim 1 having from 55 to 57 weight percent of alumina. t 20 ht 3. A concrete cement composition in accordance with A concrete cement composmon con ammg wag claim 1 having 9 weight percent of magnesium oxide.

perceint derive? from 70 weight.percent orthopbos 4. A concrete cement composition in accordance with phone acld welghidpercent alumma and 10 we'ght claim 1 having from 55 to 57 weight percent alumina and percent magnesmm on V 9 weight percent magnesium oxide.

Example 6 C't d b th Burma The concrete cement composition of Example 1 except I References I e y e H that the P 0 was derived from polyphosphoric acid. UNITED STATES PATENTS It is to be observed that the concrete cement composi- 2,324,079 7/43 Greger 106-1085 tions of the present invention rw'nchidejmlgdeis 2,391,493 12/45 Wainer et a1 106-121 particularly in those compositions where a low Welg per- 2,405,884 8/46 Greger 23 -10S centage of alumina is used. However, as heretofore indi- 2,450,952 10/48 Greger 106-121 cated, it is preferable to employ high weight percentages of alumina within the weight percentage range of to TOBIAS E. LEVOW, Primary Examiner. 

1. A CONCRETE CEMENT COMPOSITION SUITABLE FOR BLENDING WITH AGGREGATE TO PREPARE RAPID SETTING CONCRETE WHICH WILL SET WITHIN ABOUT TWO HOURS TO YIELD A NON-HYGROSCOPIC CASE CONCRETE, SAID COMPOSITION CONSISTING ESSENTIALLY OF A UNIFORM BLEND OF A MIXTURE OF A PHOSPHATE DERIVED FROM PHOSPHORIC ACID AND FROM ALUMINA, AND CONTAINING FROM 15 TO 55 WEIGHT PERCENT OF P2O5 AND FROM 45 TO 75 WEIGHT PERCENT OF A LUMINA, AND FROM 5 TO 18 WEIGHT PERCENT OF MAGNESIUM OXIDE. 